Coil apparatus



Aug. 4, 1964 H. T. HALE 3,142,970

0011. APPARATUS Filed Feb. 11, lsesfi INYENTOR. HARRY 1'. HALE.

ATTORNEY.

United States Patent 3,142,970 CGKL APPARATUS Harry T. Hale, Bridgeport, N.Y., assignor to Carrier Corporation, Syracuse, N.Y., a corporation of Delaware Filed Feb. 11, 1963, Ser. No. 257,490 11 Claims. (Cl. 62324) This invention relates to a refrigeration system, and more particularly, to a heat exchanger coil construction for use in a reverse cycle refrigeration system.

Reverse cycle refrigeration systems may employ an outdoor coil having plural rows of finned tubing. Where the capacity of the refrigeration system requires that each row of finned tubing be of relatively large area, more than one pair of refrigerant gas and liquid headers may be used to separately communicate upper and lower parts of each row of finned tubing with the refrigeration system. In that type of arrangement, the liquid refrigerant head prevailing during system operation on the cooling and defrost cycles in the lower part of each row of finned tubing comprising the outdoor coil is greater than the liquid head prevailing in the upper part of each row of finned tubing. This difference in refrigerant liquid head results in a capacity imbalance between the upper part of the outdoor coil and the lower part thereof during operation of the refrigerant system on the cooling and defrost cycles.

In refrigeration systems of the reverse cycle type, during operation on the heating cycle, a build-up of frost or ice may occur on the system outdoor coil with consequent impairment of system efficiency. To remove accumulated frost or ice from the outdoor coil, a defrost cycle operable to reverse refrigerant flow through the outdoor coil may be initiated. By this means relatively hot gaseous refrigerant in the system is directed to the outdoor coil to melt frost or ice thereon.

The build-up of frost or ice on the system outdoor coil during system operation on the heating cycle, and the reversal of the system to remove frost or ice therefrom through initiation of the defrost cycle reduces overall system efliciency. An increase therefore in the ability of the system, when operating on the defrost cycle, to effectively and rapidly remove accumulated frost or ice from the outdoor coil improves overall system efiiciency.

In an outdoor coil having one or more rows of finned tubing lying in a substantially vertical plane, Water present on the exterior surfaces of the tubing, for example, water, resulting from defrosting of the outdoor coil, tends to pass in a downward direction toward the lower part of the outdoor coil. The tendency of water on the row or rows of finned tubing to move downwardly toward the lower part of the outdoor coil enhances the propensity of the outdoor coil lower part to form frost or ice and to accumulate the largest build-up of frost or ice during the system heating cycle opeartion.

With the above considerations in mind, it is a principal object of the present invention to provide, in an outdoor coil adapted for use in a reversible refrigeration system having upper and lower sections comprised of one or more rows of substantially vertical finned tubing, an arrangement effective to more closely equalize the capacity of the upper and lower coil sections.

It is a further object of the invention to improve the ability of the reversible refrigeration system, when operating on the defrost cycle, to remove accumulated frost or ice from the system outdoor coil.

It is an additional object of the present invention to provide, in a reverse cycle refrigeration system, an arrangement operable to pass, during the system defrost cycle, relatively hot refrigerant gas directly to the area 3,142,9 1!) Patented Aug. 4., 1954 of the system outdoor coil normally having the heaviest frost or ice build-up.

It is an object of the present invention to provide a circuiting arrangement for the outdoor coil of a reversible refrigeration system having one or more rows of finned tubing effective, during the system defrost cycle, to simultaneously pass relatively hot gaseous refrigerant to spaced areas of the outdoor coil to provide rapid and uniform defrosting.

This invention relates to a coil apparatus adapted for use in a reverse cycle refrigeration system comprising the combination of plural substantially vertically disposed rows of heat exchange tubing, a first opening in the lowermost portion of each outer row of heat exchange tubing adapted to communicate with the refrigerant system gas line, a first opening in the lowermost portion of each inner row of heat exchange tubing adapted to communicate with the refrigerant system liquid line, a pair of conduits connecting a first part including the first opening of each outer row of heat exchange tubing in series flow relationship with a second part of the opposite outer row of heat exchange tubing, the first and second parts of each outer row being adjacent one another, a second opening in the lowermost portion of each outer row second parts adapted to communicate with the refrigerant system liquid line, a second opening in each inner row of heat exchange tubing adapted to place a part including the first opening of each inner row of heat exchange tubing in series flow relationship with the refrigerant system gas line, a third opening in the uppermost portion of each of the plural rows of heat exchange tubing adapted to communicate the remaining part of each plural row of heat exchange tubing with the refrigerant system gas line, and a fourth opening in the lowermost portion of the remaining part of each plural row of heat exchange tubing adapted to place each of the remaining parts of heat exchange tubing in series flow relationship with the refrigerant system liquid line.

The present invention will be more fully understood by reference to the following description read in conjunction with the accompanying drawing wherein,

FIGURE 1 is an end view of applicants novel coil construction including a schematic representation of a reverse cycle refrigeration system;

FIGURE 2 is an end view of an alternative embodiment of the present invention; and

FIGURE 3 is an end view of a modified form of applicants novel coil construction.

Referring particularly to FIGURE 1 of the drawing, there is shown an air-to-air type heat pump unit employing a refrigeration system operable on the reverse cycle principle. In apparatus of this type, a first or indoor heat exchange coil 'is disposed within or in communication with the area to be conditioned and a second or outdoor heat exchange coil is located within or in communication with the area outside the area to be conditioned, normally the ambient. The various components of the heat pump unit including the indoor and outdoor heat exchange coils are normally enclosed by one or more casings (not shown).

A compressor 10, normally positioned in the outdoor portion of the heat pump unit, discharges relatively hot gaseous refrigerant through discharge line 12 to a four- Way reversing valve 14. Valve 14, selectively operable by suitable means (not shown), reverses refrigerant flow through a portion of the refrigeration system in order to obtain the desiredheating and cooling effects.

From the reversing valve 14, hot gaseous refrigerant flows during the cooling cycle operation, illustrated by the solid line arrows, through line 18 to the outdoor heat exchange coil 20. Ambient air passed over the surface of the coil 20 by suitable fan means (not shown) effects condensation of the gaseous refrigerant passing through the outdoor coil. The liquid refrigerant formed in the heat exchange coil 20 flows through line 24 to a suitable expansion means 26 which provides the requisite pressure drop between the indoor and outdoor heat exchange coils in the refrigeration system.

The refrigerant thereafter flows through line 28 to the indoor heat exchange coil 30 serving, during the cooling cycle, as an evaporator. Refrigerant passing through the indoor coil '30 is converted into gaseous refrigerant as it extracts heat from the stream of air flowing over the indoor coil under the influence of suitable fan means (not shown). The gaseous refrigerant thereafter passes through line 34 to the reversing valve 14 and thereafter through the compressor suction line 36 to the compressor tocomplete the refrigerant flow cycle.

In operation of the heat pump described, the reversing valve 14 may be actuated to place line 12 in communication with the indoor heat exchange coil 30 and line 36 in communication with the outdoor heat exchange coil 28 when it is desired to operate the unit on the heating cycle. The'dotted line arrows illustrate the direction of refrigerant flow during the heating cycle. Under these circumstances, heat from the refrigerant flowing in the indoor coil is rejected to the stream of air flowing thereover. The rejection of heat from the refrigerant converts the gaseous refrigerant to liquid refrigerant which flows through the expansion means 26 to the outdoor coil 20-now functioning as an evaporator. The gaseous refrigerant created in the outdoor coil as a result of the heat transferred between the refrigerant and the ambient air passing thereover flows through line 18 to reversing valve 14 to the compressor 10.

While expansion means 26 has been illustrated as -a capillary type expansion means, other suitable expansion means such as a thermal valve may be contemplated.

Referring to FIGURE 1 of the drawing, the outdoor heat exchange coil 28 comprises one or more inner rows 46 of finned tubes and a pair of outer rows 44, 48 of finned tubes. Inner and outer rows 44, 46, 48 are each provided with open upper terminal and lower terminal ends 50, 51 respectively. Each of the rows 44, 46, 48 of finned tubes are interrupted by open terminals 52, 53 between, and preferably intermediate, upper and lower terminal ends 50, 51 respectively. Header60 connects the upper terminal ends 50 of rows 44, 46, 48 with the refrigerant line 18. Header'66 connects the terminals 52 in rows 44, 46, 48 with the refrigerant line 24. The upper portion ,of each of the outerrows 44, 48 between the upper terminal end 50 end terminal 52 may be interrupted by paired open terminals 54, 55. Paired terminals 5.4, 55 are preferably intermediate terminal end 50 andterminal 52. A pair of cross-over conduits 78', 72 connect terminals 55, 54 respectively of row 44 to the opposite terminals 54, 55 of row 48.

Header 61 connects terminal 53 of the inner row or rows 46 of finned tubing to refrigerant line 18. Header 62 connects the lower terminal end 51 of each of the outer rows 44, 48 with the refrigerant line 18. A header 67 connects lower terminal end 51 of the inner row or rows 46 to the refrigerant line 24.

The lowerportion of eachof theouter rows 44, 48 of finned tubes between terminal 53 and lower. terminal end 51 is interrupted by paired open terminals 56, 57. Paired terminals 56, 57 are preferably intermediate terminal end 51 and terminal 53. Header 68 connects terminals 56 of the outer rows 44, 48 with the refrigerant line 24. A pair of conduits '74, 76 connect terminals 57 of each of the outer rows 44, 48 to the terminals 53 of the opposite outside row 48, 44 respectively.

During the cooling and defrost cycles, refrigerant from header 6t) flows downwardly through the rows 44, 46, 48 of finned tubes comprising the outside coil 20 into header 66. Refrigerant passing downwardly through the upper portion of each outer row 44, 48 flows through the crossover conduits 7t), 72 respectively into the remaining portion of the opposite outer row for discharge into header 66. Refrigerant from header 61 flows downwardly through the inner row or rows 44 of finned tubes into header 67. Refrigerant from header 62 flows upwardly through each outer row 44, 48 and conduits 74, 76 respectively, and downwardly through the opposite outer row 48, 44 into header 68.

During system operation on the heating cycle the direction of refrigerant flow relative to outside coil 20 is reversed, refrigerant entering coil 20 through headers 66, 67 and 68 and discharging therefrom through headers 60, 61, 62.

In the modification illustrated by FIGURE 2 of the drawing wherein like numerals refer to like parts, the inner row or rows 46 of coil 20 are interrupted by paired open terminals 80, 82 between, and preferably intermediate, terminal 53 and lower terminal end 51 thereof. Header 68 connects to the terminal thereof. It is understood that header 68 also connects to terminals 56 of the outer rows 44, 48. A conduit 85 connects terminal 80 with terminal 53 of the inner row or rows 46. Lower terminal end 51 of the inner rows 46 connects with the header 62. Header 62 additionally connects to the lower terminal ends 51 of outer rows 44, 48.

In the embodiment illustrated by FIGURE 3 of the drawing, wherein like numerals refer to like parts, outdoor coil 20 comprises rows 102, 104 of finned tubes having upper and lower terminal ends 186, 108. A header 119 connects lower terminal end 108 of each of the rows 102, 104 with the refrigerant system line 18. Each of the rows 102, 104 is interrupted by paired open terminals 116, 118 between, and preferably intermediate, upper and lower terminal ends 106, 188 respectively. A pair of conduits 128, 122 connect terminals 118 of rows 102, 184 with the upper terminal end 106 of the opposite row 104, 102 respectively. Header 126 connects terminals 116 of rows 182, 104 with the refrigerant line 24. It is understood that outdoor coil 20 may include one or more rows of finned tubes between rows 102, 104. In

that construction, the upper terminal end of each of header means to the refrigerant line 24. Alternately,

each inner row of finned tubes may be interrupted by paired terminals between, and preferably intermediate, the upper and lower terminal ends thereof with a suitable conduit connecting that terminal nearest the lower terminal end with the upper terminal end thereof. The lower terminal end and the remaining terminal of each inner row may be connected to the refrigerant lines 18 and 24 respectively by suitable header means.

By applicants unique coil construction, a reduction in the refrigerant liquid head prevailing in the lower portion of the rows of finned tubes comprising the coil is effected to more closely equalize the capacity of the several portions of the coil. Further, the effectiveness of the system defrost is enhanced since applicants coil construction serves to pass, during the system defrost cycle, a portion of the relatively hot gaseous refrigerant from the system directly to the lower portion of the coil, the area where the heaviest build-up of frost or ice normally occurs.

While I have described preferred embodiments of the present invention, it is understood that this invention may be otherwise embodied within the scope of the following claims.

I claim: 1. Outdoor coil apparatus adapted for use in a reverse cycle refrigeration system, the combination of (l) plural substantially vertically disposed rows of heat exchange tubing, (2) each of said outer rows of heat exchange tubing having a first opening in the lowermost portion thereof adapted to communicate with the refrigeration system reversing means for receiving the refrigerant during system cooling and defrost cycles, said refrigerant being adapted to pass upwardly through a first part of each outer row,

(3) first conduit means operable to pass said refrigerant upwardly from said first part of each outer row to the opposite outer row, said refrigerant being adapted to pass downwardly through a second part of each outer row, and

(4) said second part of each outer row having a second opening adapted to communicate with the refrigeration system expansion means through which said refrigerant is adapted to pass to said system.

2. Coil apparatus according to claim 1 in which said first and second parts of said outer rows are substantially equal to one another.

3. Coil apparatus according to claim 1 in which said first and second parts of each of said outer rows are adjacent one another, each outer row of heat exchange tubing having a third opening spaced from said first conduit means in the uppermost portion thereof adapted to communicate with said reversing means for receiving refrigerant during system cooling and defrost cycles, said refrigerant being adapted to pass downwardly through each outer row, each outer row having a fourth opening between said third opening and said first conduit means adapted to communicate with said expansion means through which said refrigerant is adapted to pass to the system.

4. Coil apparatus according to claim 1 in which said plural rows of heat exchange tubing include at least one inner row of heat exchange tubing between said outer rows having a first opening adapted to communicate with said reversing means to receive refrigerant during system cooling and defrost cycles and a second opening spaced from said first opening adapted to communicate with said expansion means through which said refrigerant is adapted to pass to said system.

5. Coil apparatus according to claim 4 in which said second opening is in the lowermost portion of said inner row, said inner row having a third opening spaced from said first opening in the uppermost portion thereof adapted to communicate with said reversing means for receiving refrigerant during system cooling and defrost cycles, said refrigerant being adapted to pass downwardly through said inner row, said inner row having a fourth opening between said first and third openings adapted to communicate with said expansion means through said refrigerant is adapted to pass to said system.

6. In coil apparatus for use in a reversible refrigeration system including reversing means having a refrigerant gas line leading therefrom and expansion means having a refrigerant liquid line leading therefrom, the combination of (1) first and second substantially vertically disposed rows of heat exchange tubing, each having a first opening in the lowermost portion thereof adapted to communicate with the refrigerant system gas line,

(2) first conduit means connecting a first part including said first opening of each of said first and second rows in series flow relationship with a second part of the opposite second and first rows respectively, and

(3) a second opening in the lowermost portion of each of said second parts adapted to communicate said first and second rows with the refrigerant system liquid line.

7. Coil apparatus according to claim 6 in which said first and second parts of each of said first and second rows are adjacent one another, each of said first and second rows having a. third opening spaced from said first conduit means in the uppermost portion thereof adapted to communicate each of said first and second rows with the refrigerant system gas line, second conduit means between said third opening and said first conduit means connecting said first and second rows in series flow relationship with the opposite second and first rows respectively, each of said first and second rows having a fourth opening between said first and second conduit means adapted to communicate with the refrigerant system liquid line.

8. Coil apparatus according to claim 7 including a third row of substantially vertically disposed heat exchange tubing between said first and second rows having a first opening in the lowermost portion thereof adapted to communicate with the refrigerant system liquid line and a second opening adapted to place a part of said third row including said first opening in series flow relationship with the system gas line, a third opening spaced from said second opening in the uppermost portion thereof adapted to communicate with the refrigerant system gas line and a fourth opening between said second and third openings to place said third row including said third opening in series flow relationship with the refrigerant system liquid line.

9. In coil apparatus for use in a reversible refrigeration system having refrigerant metering means and reversing means, the combination of (1) first and second rows of heat exchange tubing having upper and lower terminal ends respectively,

(2) first header means connecting said first and second row lower terminal ends with said reversing means,

(3) conduit means connecting a first portion including the lower terminal end of each of said first and second rows in series fiow relationship with a second portion of the other of said second and first rows at said second and said first row upper terminal ends respectively, and

(4) second header means connecting said first and second row second portion with said metering means.

10. Coil apparatus according to claim 9 including a third row of heat exchange tubing intermediate said first and second rows having upper and lower terminal ends respectively, third header means connecting said third row upper terminal end with said reversing means, and fourth header means connecting said third row lower terminal end with said metering means.

11. Coil apparatus for use in a reversible refrigeration system having refrigerant metering means and reversing means, the combination of (1) plural substantially vertically disposed rows of heat exchange tubing,

(2) each outer row of said heat exchange tubing having a first opening in the lowermost portion thereof adapted to communicate with said reversing means,

(3) each inner row of heat exchange tubing having a first opening in the lowermost portion thereof adapted to communicate with said metering means,

(4) a pair of conduits connecting a first part including said first opening of each outer row of heat exchange tubing in series flow relationship with a second part of the opposite outer row of heat exchange tubing, said first and second parts of each outer row being adjacent one another,

(5) each of said second outer row parts having a second opening in the lowermost portion thereof adapted to communicate with said metering means,

(6) each of said inner rows of heat exchange tubing having a second opening adapted to place a part including said first opening of each of said inner rows of heat exchange tubing in series flow relationship with said metering means,

(7) each of said plural rows of heat exchange tubing having a third opening in the uppermost portion thereof adapted to communicate the remaining part 17 of each of said plural roWs of heat exchange tubing with said reversing means,

(8) and a fourth opening in the lowermost portion of each of said remaining parts of said plural rows of heat exchange tubing adapted to place each of said 5 remaining parts in series flow relationship with said metering means. I i

References Cited in the file of this patent UNITED STATES PATENTS Malkoff Feb. 16, 1954 Walter Aug. 9, 1955 Biehn a. Sept. 17, 1957 Warrington Mar. 17, 1959 Burnett Mar. 13, 1962 Patent No. $142,970 August 4 1964 Harry T, Hale It is hereby certified. that err ent requiring correction and th corrected below.

or appears in the above numbered pata,t the said Letters Patent should read as Column l line 56, for "opeartion" read operation column 3 line 51 for "end",, second occurrence, read and column 5 line 5O after "through" insert which Signed and sealed this 2nd day of February 1965..

(SEAL) Attest:

ERNEST W. SWIDER' Commissioner of Patents 

6. IN COIL APPARATUS FOR USE IN A REVERSIBLE REFRIGERATION SYSTEM INCLUDING REVERSING MEANS HAVING A REFRIGERANT GAS LINE LEADING THEREFROM AND EXPANSION MEANS HAVING A REFRIGERANT LIQUID LINE LEADING THEREFROM, THE COMBINATION OF (1) FIRST AND SECOND SUBSTANTIALLY VERTICALLY DISPOSED ROWS OF HEAT EXCHANGE TUBING, EACH HAVING A FIRST OPENING IN THE LOWERMOST PORTION THEREOF ADAPTED TO COMMUNICATE WITH THE REFRIGERANT SYSTEM GAS LINE, (2) FIRST CONDUIT MEANS CONNECTING A FIRST PART INCLUDING SAID FIRST OPENING OF EACH OF SAID FIRST AND SECOND ROWS IN SERIES FLOW RELATIONSHIP WITH A SECOND PART OF THE OPPOSITE SECOND AND FIRST ROWS RESPECTIVELY, AND (3) A SECOND OPENING IN THE LOWERMOST PORTION OF EACH OF SAID SECOND PARTS ADAPTED TO COMMUNICATE SAID FIRST AND SECOND ROWS WITH THE REFRIGERANT SYSTEM LIQUID LINE. 